Gas dish washer



Sept. 24, 1963 J. w. CLAYWELL GAS DISH WASHER 3 Sheets-Sheet 1 Filed May15, 1960 INVENTOR p 1963 J, w. CLAYWELL 3,104,669

GAS DISH WASHER Filed May 15, 1960 3 Sheets-Sheet 2 ZZO Sept. 24, 1963J. w. CLAYWELL 3,104,669

GAS DISH WASHER Filed May 15, 1960 s Sheets-Sheet 3 i w mm],

TFMPEEflTl/EE CONTROL VH1. VE'

IN V EN TOR.

DE VICE United States Patent 3,104,669 GAS DISH WASHER Jack W. Claywell,Wisconsin Rapids, Wis, assignor to Preway Inc, a corporation ofWisconsin Filed May 13, 19%, Ser. No. 28,895 7 Claims. (Cl. 134-57) Thisinvention relates to an article washing apparatus and more particularlyto a dishwasher utilizing gas in operation thereof.

An object of this invention is to provide a new and improved dishwasherutilizing gas for heating of wash and rinse water as well as heating ofdrying air.

Another object of the invention is to provide a dishwasher utilizing gasin operation thereof having a tub with a sump at the base thereof, awater circulating system for circulating water including water spraymechanism, means for heating water in the sump comprising a heatexchanger member passing through the sump at a level above a water drainoutlet from the sump, a gas burner associated with the heat exchangermember, and a flue externally of the tub connected to said exchangermember whereby combustion gases pass through the tube and flue, and acirculating air system for circulating air within the tub including anair passage extending generally between the top and bottom of the tubexteriorly thereof, and an air blower in said passage, said passage andflue being arranged in heat exchange relation.

Further objects and advantages will become apparent from the followingdetailed description taken in connection with the accompanying drawingsin which:

FIG. 1 is a perspective view of the dishwasher with a part of a cabinetside wall removed, the door of the unit shown in open position and theracks removed;

FIG. 2 is a perspective elevational view looking toward the rear of thecabinet with a part of the cabinet wall removed;

FIG. 3 is a horizontal section on an enlarged scale taken generallyalong the line 33 in FIG. 1 with the door omitted and the tub bottombroken away;

FIG. 4 is a fragmentary vertical section taken along the line 4-4 inFIG. 3;

FIG. 5 is a fragmentary vertical section taken generally along the line5-5 in FIG. 4;

FIG. 6 is a fragmentary section on an enlarged scale taken generallyalong the line 66 in FIG. 4;

FIG. 7 is a fragmentary section on an enlarged scale taken generallyalong the line 77 in FIG. 1;

FIG. 8 is a fragmentary horizontal section taken generally along theline 8-8 in FIG. 7; and

FIG. 9 is a schematic drawing of the control circuit for the dishwasher.

While this invention is susceptible of embodiments in many differentforms, there is shown in the drawings and will herein be described indetail an embodiment of the invention with the understanding that thepresent disclosure is to be considered as an exemplification of theprinciples of the invention and is not intended to limit the inventionto the embodiment illustrated. The scope of the invention will bepointed out in the appended claims.

As shown in the drawings, the dishwasher has an enclosing cabinet withside walls 10 and 11 and a back wall 12 with a tub 15 mounted thereinand a door 16 forming a closure for the tub 15 as well as an enclosurefor a front wall 17 of the cabinet.

The tub 15 has side walls 20 and 21, a back wall 22, and a top wall 23as well as a bottom 24 having a generally rectangular well-like sump 25mounted centrally thereof.

The water system for the dishwasher includes filling 3,104,659 PatentedSept. 24, 1963 of the tub 15 and circulation of water within the tub andcomprises a filling pipe 28 adjacent the rear wall 22 of the tub whichdischarges water into a blow off valve mechanism 29 which alsoconstitutes an air gap fill to avoid syphoning action. As shown in FIG.5 the water passes through the blow off valve 29 into the tub. Water forboth washing and rinsing then passes from the sump 25- through arecirculating water outlet 30 and a hose connection 31 to arecirculating pump 32. The outlet of the pump 32 connects to a pair ofpipes 33 and 34 each of which connect to a duct 35 and 36, respectively,located externally of the tub side walls 20 and 21. Each of these ductsconnects through suitable bearings to one of a pair of rotatable waterspray arms 37 and 38 having a series of domes 39 and 40 with slitsformed therein whereby a water spray emits from the spray arms. Reactionforces due to the water spray cause rotation of the spray arms 37 and 38to direct water onto glasses, dishes, cups and other utensils mounted inracks disposed within the tub 15. A strainer 41 is mounted within thesump in covering relation with the outlet 30 to strain foreign matterfrom the water and prevent passage thereof to the outlet 30.

Means for heating water in the sump utilizing gas embodies a heatexchange member 44 in the form of a tube positioned in the sump andhaving a bend 45 therein to have a greater area of exposure within thesump. An end 46 of the member outside the sump and beneath the bottom 24of the tub has a gas burner 47 positioned therein. With the gas burner47 operating as it does in Wash,'rinse and drying cycles, combustiongases pass through the exchanger 44 to transfer heat therefrom to waterlocated in the sump. In a normal fill operation, sufficient water isdirected into the tub to have its level generally above the top of theexchange tube. The exchanger 44 has another end 48 connected to a flue49 passing upwardly externally of the tub rear wall 22 for connection tosuitable ducts for exhaustion of the gases.

Drying of dishes and utensils is obtained by the principle of cold wallcondensation whereby water condensing upon the inner side of the tubwalls runs down into the sump. To facilitate drying, a circulating airsystem is provided including an air passage 50 located externally of thetub rear wall 22 having an air inlet connection 51 with the tub rearwall 22 and an air outlet connection 52 with the tub rear wall and witha circulating fan 53 associated with the air outlet opening.

'With the fan in operation, air is caused to circulate through the tuband through the passage 50. To facilitate drying, the air is heated bycontact with the exchanger 44, with the burner 47 operating which isexposed during a drying cycle due to exhaustion of water from the sump25. Heating of the air is also caused by a heat interchange connectionbetween the fiue 49 and the circulating air passage 5-0 as shown inFIGS. 2 and 6. The air passage 50 is constructed to have the flue 49pass therethrough, whereby heat exchange takes place between gasescontained in said two parts.

At the completion of a wash cycle, the water is drawn from the sump 25through a drain outlet 55 which by a hose 56 connects to a pump 57connected to a drain line 58. The withdrawal of water from the sump 25by the pump 57 results in washing off the strainer 41 to keep thestrainer relatively free of debris. It will be noted that the drainoutlet 55 is at the bottom of the sump and beneath the exchange member44 whereby the tube is exposed in a drying cycle.

The control system for the dishwasher is shown in FIG. 9 and the cycleof the dishwasher is obtained from a timer 60 having lines 61 and'62'connected to a source of electricity. The timer determines the operationof the success 3 recirculating pump 32 and the drain pump 57 bycontrolling operation of a pair of motors 63 and64 respectivelyassociated with these pumps. The timer also controls a solenoid valve 65which is connected into the line 28 supplying water to the tub from awater line 66.

Gas is supplied to the burner 47 from a source 67 through a temperaturecontrol valve 68 having an outlet pipe 69 connected to the burner 47.The pipe 69 has a solenoid control valve 70 controlled by the timer 60to control the time during which the burner 47 is operative. Anauxiliary gas pipe '71 extends from the control valve 68 to supply apilot 72 for the burner 47. The pilot is of the thermal element typewhereby failure of the burner 47 to ignite results in a signal to thecontrol valve 68 through lines 73 and 74 to shut oil the supply of gasto the burner.

The temperature control valve 68 also functions to regulate the flow ofgas to the burner 47 to maintain a predetermined temperature of thewater in the sump 25 and this action is obtained by a temperaturesensing device 75 positioned adjacent the sump as shown in FIG. 5. Asone example, the sensing device 75 may be in the form of a mercury bulbunit which delivers a signal to the control valve 68. The control valve68, as an example, may be a commercially available Robertshaw-FultonBJ'FM Oven Thermostat.

In operation of the dishwasher upon closure of the door 16, the timer 60is placed in operation and the machine is started in a wash cycle inwhich the solenoid valve 65 is operated to deliver water into the tub15. The solenoid valve 70 in the gas line is also operated to emit gasfrom the burner 47 which is ignited by the pilot 72 and the combustiongases pass through the exchanger 44 to heat Washwater in the sump. Aftera desired interval, the motor 63 for the recirculating pump 32 isoperated to draw water from the sump and direct it to the spray arms 37and 38 mounted rotatably on the side walls of the tub, whereby water isdirected upon dishes and utensils within the tub. After a desiredinterval of washing, the timer 6% then shuts d the motor 63 and operatesthe motor 64 to operate the drain pump 57 to exhaust water from the tub.The motor 64 is then stopped and the solenoid valve 65 operated todirect water into the sump for rinsing. During this time the burner 47may still operate to heat the rinse water to a suitable temperature withthe temperature at this time and during the wash cycle being maintainedat a desired level by the temperature sensing device 75 controlling thevalve 63. After the desired rinsing operation by operation of pump 32,the timer 60 stopsv the motor 63 and the motor 64 is operated to againdrain water from the tub. At this time the timer operates a motor 80 forthe fan 53 to cause drying air to circulate through the tub with theburner 47 still operating. After a desired interval, this operation isstopped and the cycle is completed.

In order to insure positive closure of the door 16, against the tub 15,an overcenter latch is provided with a latch member 81 pivoted by a pin82 to a bracket 83 secured to a mounting member 84- attached to the topwall 23 of the tub. The latch member is connected to a slidable link 85having a slot 86 slidable on a pin 87 and the latch member is providedwith a cam slot 83 for co-action with a pin 89 carried by a plate 99attached to the door 16. The front of the cabinet is provided withopening 91 of a size to receive the roller 39' when the door 16 is movedto closed position as shown in FIGS. 7 and 8. With the door in closedposition, the latch member 81 engages a blade 91 to close a switch 92which is in the main line of the control circuit as shown in FIG. 9.Opening of the door 16 causes the pin 89- to swing the latch membercounterclockwise as viewed in FIG. 8 to an extreme position in abutmentwith a pad 93 and the latch member 81 is held in this position by aspring 94 until the door is again closed and the pin 89' causes 4pivoting of the latch member to the position shown in FIG. 8.

The blow 05 valve 29 previously referred to is needed extends within thetub for holding a pool of water and has a leg 1'32 with an endterminating at a level slightly above the upper edge of the openingwhereby the water blocks the opening. This distance is approximately 1of an inch and thus the blow off valve operates, when the pressurewithin the tub equals an amount sufiicient to depress the water levelbetween the back wall 22 and the leg 1&2 of the plate 191 suificient touncover the upper edge of the opening 100, to permit air to escape fromwithin the tub. 'The outer side of the blow off valve to the outside ofthe tub back wall 22 is wider than the inner side whereby waterdisplaced by depressing the level 7 thereof within the tub has more roomto spread out an more quickly permit the valve to function. 1

In order to support cups, glasses and dishes within th tub, an upperrack is supported from a pair of side tracks 106 and 107 by brackets 108and 109 attached to the rack and each having rollers 110 and 111, respectively. There are a pair of these brackets at the front of the rack anda similar pair at the back whereby the rack is rollingly supportedwithin the tub and maybe drawn toward the front thereof to overlie theopen door 16 to facilitate loading and unloading thereof. A lower rackis supported on side tracks 116 and 117 by similar brackets and rollersfor movement into and out of the tub. The racks 105 and 115 may haveadditional removable sections that can be placed where convenient foruse.

I claim:

l. A dishwasher utilizing gas in operation thereof comprising a cabinet,a tub within the cabinet having a sump at the base thereof with a drainoutlet, a water circulating cystem including water spray mechanism forspraying water within the cabinet, a recirculating water outlet from thesump, and means for directing water from the recirculating water outletto said mechanism, means for heating water in the sump comprising a gasheat ex: change tube passing through the sump at a level above the drainoutlet, a gas burner operatively associated with the exchange tube and aflue externally of the tub connected to said exchange tube wherebycombustion gases pass through the tube and flue, and a circulating airdrying system including an air passage extending generally between thetop and bottom of the tub exteriorly thereof, and an air blower in saidpassage, said passage and fine being arranged in heat exchangingrelation.

2. A dishwasher as defined in claim 1 including a control for cyclingthe dishwasher, a latch for holding a tub closing door in closedposition, and a switch responsive to the latch position when the door isclosed for rendering said control operative.

3. An article washing apparatus comprising, a tub with a bottom Wall anda sump, means for circulatingliuid within the tub, and means for heatingfluid in said sump and any water above the level of the tub bottom wallincluding a heat exchange member passing through the sump, a gas burneroperatively associated with said member to direct hot gasestherethrough, flue means connected to said heat exchange member toconvey combustion gases away from said apparatus, means for facilitatingthe drying of articles within the tub comprising, a circulating airsystem which llows air within the tub and over the exchange member, andwhich provides a heat exchanging association between said flue means andsaid circulating air system.

4. A dishwasher utilizing gas in operation thereof coinprising a tubhaving a centrally located sump at the base thereof, said sump having abottom with a drain outlet and a recirculating water outlet with astrainer over the latter, means for spraying water within the tubincluding rotatable wash arms remote from the .tub base and arecirculating pump connected to the recirculating water outlet, andmeans for heating water in the sump including an exchange memberhorizontally disposed in the sump above the bottom and in unobstructedrelation with the tub wall, a gas burner operatively associated with theexchange member to direct combustion gases therethrough, a control forsaid gas burner, and means for sensing the water temperature in the sumpfor determining the action of said control.

5. A dishwasher utilizing gas in operation thereof comprising a cabinetwith walls, a tub within the cabinet having a bottom wall above thelowest part of the cabinet and opposite side Walls, a Water collectingsump depending from the bottom wall of the tub for collecting a quantityof water therein before the water surface reaches the level of the .tubbottom Wall, said sump having a peripheral wall spaced a substantialdistance from the cabinet walls, a heat exchange tube extending throughthe sump for unobstructed exposure to the tub and having a height tospan a major part of the sump height, a gas burner positioned within anend of said tube for burning of gas therein, a pair of rotatably mountedwash arms extending from the side walls of the tub, and means fordirecting water from the sump to the wash arms.

6. A dishwasher utilizing gas in operation thereof comprising a cabinetwith walls, a tub within the cabinet having a bottom wall above thelowest part of the cabinet and opposite side walls, a water collectingsump depending from the bottom wall of the tub for collecting a quantityof water therein before the water surface reaches the level of the tubbotom wall, said sump having a peripheral wall spaced a substantialdistance from the cabinet Walls, a heat exchange tube extending throughthe sump for unobstructed exposure to the tub with both ends of the tubeextending externally beyond the sump peripheral Wall, a gas burnerpositioned within an end of said tube beneath the tub bottom wall forburning of gas therein, a pair of rotatably mounted wash arms extendingfrom the side walls of the tub, means for directing water from the sumpto the wash arms, and means operatively associated with the other end ofthe tube for venting the combustion gases.

7. A dishwasher utilizing gas in operation thereof comprising a cabinetwith Walls, a tub within the cabinet having a bottom wall above thelowest part of the cabinet and opposite side Walls, a water collectingsump depending from the bottom Wall of the tub for collecting a quantityof water therein before the water surface reaches the level of the tubbottom wall, said sump having a peripheral wall spaced from the cabinetwalls, a heat exchange tube extending through the sump for unobstructedexposure to the tub and having a height to span a major part of the sumpheight, a gas burner positioned within an end of said tube for burningof gas therein, and means for circulating water within the tub.

References Cited in the file of this patent UNITED STATES PATENTS1,272,478 Lukus July 16, 1918 1,559,727 Merseles et al Nov. 3, 19251,656,139 Breton June 10, 1928 1,687,458 Lancelot Oct. 9, 1928 1,896,149Zademach Feb. 7, 1933 2,081,636 Miners May 25, 1937 2,123,809 Seitz July12, 1938 2,304,438 Bilde Dec. 8, 1942 2,618,282 Ornas Nov. 18, 19522,621,666 Hiort af Ornas Dec. 16, 1952 2,655,024 Sway Oct. 13, 19532,666,439 Bechtol Jan. 19, 1954 2,825,349 Keliher et a1 Mar. 4, 19582,841,136 Pettit July 1, 1958 3,026,628 Berger et a1 Mar. 27, 1962FOREIGN PATENTS 65,237 Holland Feb. 15, 1950 577,825 Canada June 16,1959

7. A DISHWASHER UTILIZING GAS IN OPERATION THEREOF COMPRISING A CABINETWITH WALLS, A TUB WITHIN THE CABINET HAVING A BOTTOM WALL ABOVE THELOWEST PART OF THE CABINET AND OPPOSITE SIDE WALLS, A WATER COLLECTINGSUMP DEPENDING FROM THE BOTTOM WALL OF THE TUB FOR COLLECTING A QUANTITYOF WATER THEREIN BEFORE THE WATER SURFACE REACHES THE LEVEL OF THE TUBBOTTOM WALL, SAID SUMP HAVING A PERIPHERAL WALL SPACED FROM THE CABINETWALLS, A HEAT EXCHANGE TUBE EXTENDING THROUGH THE SUMP FOR UNOBSTRUCTEDEXPOSURE TO THE TUB AND HAVING A HEIGHT TO SPAN A MAJOR PART OF THE SUMPHEIGHT, A GAS BURNER POSITIONED WITHIN AN END OF SAID TUBE FOR BURNINGOF GAS THEREIN, AND MEANS FOR CIRCULATING WATER WITHIN THE TUB.